Distortion in sound reproducing equipment is familiar to anyone who has heard a worn-out jukebox, or an overloaded public address system. This harsh, unpleasant sound presents the essential nature of all distortion: What comes out of the system is different from what went in! In a CATV system distortion does not show up in the same way, but it is present, and it places restrictions on ·system operation which must be understood if it is to be intelligently planned and operated.